CustomJS API

Name: CustomJS API API
Brand: CustomJS API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentDeveloper ToolsTesting QaapiKey9 EndpointsREST

For Agents

Convert HTML and Markdown to PDF, capture web screenshots, scrape HTML, and run arbitrary JavaScript - all over a simple HTTP API.

Quickstart

Get started with CustomJS API in minutes using your preferred integration method.

# Add to your MCP client config (Claude Desktop, Cursor, Windsurf)
{
  "jentic": {
    "url": "https://api.jentic.com/mcp",
    "auth": "oauth"
  }
}

# Then ask your agent:
"convert HTML to PDF"

# → Jentic returns the GET /events tool with parameter schema, agent executes.

Capabilities

What an agent can do with CustomJS API API.

Convert raw HTML to a downloadable PDF via POST /html2pdf

Render Markdown to PDF in a single call via POST /markdown2pdf

Capture a full-page web screenshot of any URL via POST /screenshot

Scrape rendered HTML from a URL after JavaScript execution via POST /scraper

Execute custom JavaScript in a sandbox via POST /__js1- and return the result

GET STARTED

Start building with CustomJS API API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for CustomJS API, keeping it validated and agent-ready.

Jentic publishes the only available OpenAPI specification for CustomJS API, keeping it validated and agent-ready. CustomJS is a hosted automation toolkit for HTML-to-PDF and Markdown-to-PDF conversion, full-page web screenshots, HTML scraping, on-demand JavaScript execution, and lightweight hosted HTML pages. The 9 endpoints let you turn raw HTML or a URL into rendered output without operating a headless browser yourself. Authentication is a single X-API-Key header.

Use Cases

Patterns agents use CustomJS API API for, with concrete tasks.

★ Generate PDF receipts on demand

Render a templated HTML invoice or receipt to PDF without running a headless Chrome cluster. POST the HTML body to /html2pdf and store the resulting PDF, or attach it to an email. Works well for low-volume back-office workflows where managing Puppeteer or wkhtmltopdf is overkill.

Render the HTML invoice for order 4521 by calling POST /html2pdf and return a downloadable PDF link.

Periodic visual snapshots of a page

Capture timestamped screenshots of a marketing page or competitor pricing page on a schedule. POST /screenshot accepts a URL and returns a rendered image you can store in object storage. Pair it with a cron-style scheduler to build a visual change log.

Take a screenshot of https://example.com/pricing and store the PNG with today's date as the filename.

Lightweight scraping for SPA content

Pull rendered HTML out of a JavaScript-heavy single-page app without standing up your own browser pool. POST /scraper executes the page in a real browser and returns the post-render HTML, which a downstream parser can extract into structured records.

Scrape the rendered HTML from https://example.com/products and return the body element only.

PDF and screenshot tools for AI agents via Jentic

Give an autonomous agent a way to produce documents and visuals as part of its workflow. The agent searches Jentic for 'convert HTML to PDF', loads the schema, and executes the call - the API key is held in the vault rather than the agent's prompt.

Through Jentic, call POST /html2pdf with the HTML body of a generated report and attach the PDF to an outbound email.

Key Endpoints

9 endpoints — jentic publishes the only available openapi specification for customjs api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/html2pdf

Convert HTML to PDF

POST

/markdown2pdf

Convert Markdown to PDF

POST

/screenshot

Capture a web page screenshot

POST

/scraper

Scrape post-render HTML from a URL

POST

/__js1-

Execute custom JavaScript and return the result

POST

/pages/page/upsert-html

Create or update a hosted HTML page

POST

/html2pdf

Convert HTML to PDF

POST

/markdown2pdf

Convert Markdown to PDF

POST

/screenshot

Capture a web page screenshot

POST

/scraper

Scrape post-render HTML from a URL

POST

/__js1-

Execute custom JavaScript and return the result

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

The CustomJS X-API-Key is stored encrypted in the Jentic vault. Agents call the API through Jentic with a scoped execution token - the raw key never reaches the agent's prompt context.

Intent-based discovery

Agents search by intent (e.g. 'convert HTML to PDF' or 'take a screenshot of a webpage') and Jentic returns the matching CustomJS operation and schema, so the agent picks the right endpoint without reading docs.

Time to first call

Direct CustomJS integration: a few hours for HTTP plumbing, key handling, and error retries. Through Jentic: under 15 minutes - search, load, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Alternative

html2pdf.app

Single-purpose HTML-to-PDF conversion API

Pick html2pdf.app if you only need PDF conversion and want a simpler surface; choose CustomJS when you also need screenshots, scraping, or hosted pages.

Alternative

Urlbox

Specialised website screenshot and PDF rendering API

Choose Urlbox for high-volume screenshot workloads with fine-grained viewport and waiting controls; CustomJS is the lighter generalist.

Complementary

PDF.co

Broader PDF processing toolkit (parsing, splitting, OCR)

Use PDF.co alongside CustomJS when you need to parse or transform existing PDFs after generating them.

FAQs

Specific to using CustomJS API API through Jentic.

Why is there no official OpenAPI spec for CustomJS API?

CustomJS does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call CustomJS via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.

What authentication does the CustomJS API use?

An API key passed in the X-API-Key header on every request. Through Jentic, the key is stored in the encrypted vault and injected at execution time so it never appears in agent prompts or logs.

Can I generate a PDF from HTML with CustomJS?

Yes. POST /html2pdf with the HTML body returns a rendered PDF. Use POST /markdown2pdf if your source is Markdown - CustomJS handles the conversion in one call.

Can I scrape JavaScript-rendered pages with CustomJS?

Yes. POST /scraper executes the target URL in a real browser and returns the post-render HTML, which is what you typically need for single-page apps where the source HTML is empty.

What are the rate limits for the CustomJS API?

Rate limits depend on your CustomJS plan rather than the spec. Watch for 429 responses, back off, and check your account dashboard for the per-minute and per-day quotas tied to your tier.

How do I convert HTML to PDF through Jentic?

Run pip install jentic, search for 'convert HTML to PDF', load the /html2pdf schema, and execute with your HTML body. Jentic returns the rendered PDF response without your code touching the API key.